note 123355 added to function.gmp-popcount

If you don't have gmp extension enabled (or don't want to use it for any reason), you can get popcount of an int using decbin() and substr_count(). <?php $int1 = 133; $bin1 = decbin($int1); // "10000101" echo substr_count($bin1, "1"); // Result: 3 ?> Being a string-comparison this is far less efficient than gmp_popcount() (for which there is a dedicated instruction on most if not all modern processors), but may be handy if gmp is unavailable, or in non-performance-critical code that doesn't otherwise need it. ---- Server IP: 208.43.231.9 Probable Submitter: 62.49.1.208 ---- Manual Page -- http://php.net/manual/en/function.gmp-popcount.php Edit -- https://master.php.net/note/edit/123355 Del: integrated -- https://master.php.net/note/delete/123355/integrated Del: useless -- https://master.php.net/note/delete/123355/useless Del: bad code -- https://master.php.net/note/delete/123355/bad+code Del: spam -- https://master.php.net/note/delete/123355/spam Del: non-english -- https://master.php.net/note/delete/123355/non-english Del: in docs -- https://master.php.net/note/delete/123355/in+docs Del: other reasons-- https://master.php.net/note/delete/123355 Reject -- https://master.php.net/note/reject/123355 Search -- https://master.php.net/manage/user-notes.php